<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        #signal{
            display: none;
        }
    </style>
</head>
<body>
    <form action="404" method="post">
        请输入密码：<input type="password" name="pub">
        <input type="text" name="time" class="time" style="display:none;">
        <input type="submit" value="提交" class="submit">
        <input id="signal" name="signal" value=<%= signal %>></input>
    </form>

    <script>
        var button = document.querySelector(".submit");
        var time1 = document.querySelector(".time");
        button.addEventListener("click",function(){
            var time = new Date();
            time1.value = time.getTime();
        });
    </script>
</body>
</html>